JPH054384B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the general formula () (In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group, and R ₃ represents an alkylene group having 1 to 4 carbon atoms.) 2,2,6,6-tetramethylpiperidine represented by This invention relates to derivatives and methods for producing the same. 2,2,6,6- represented by the above general formula ()
Tetramethylpiperidine derivatives are new compounds synthesized by the present inventors for the first time and have not been described in any literature, and they have a stabilizing effect on synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, polyurethane, and ABS resin, and are particularly effective against deterioration caused by light. It is a useful compound as a stabilizer. Such 2,2,6,6-tetramethylpiperidine derivatives have the general formula () (In the formula, R ₁ represents a hydrogen atom or a methyl group.) 4-Amino-2,2,6,6-tetramethylpiperidine compound represented by the general formula () (In the formula, X is a halogen atom, and R ₃ has 1 to 1 carbon atoms.
4 represents an alkylene group, and R ₄ represents a hydrogen atom or a lower alkyl group. ) by reacting the halogenated carboxylic acids shown in
Then the general formula () (In the formula, _R2 represents a hydrogen atom or a methyl group.) Produced by reacting a 4-hydroxy-2,2,6,6-tetramethylpyridine compound represented by the following in the presence of a basic catalyst. I can do it. In the first step reaction of this method, 4-amino-2,2,6,6-
The reaction molar ratio of the tetramethylpiperidine compound and the halogenated carboxylic acid represented by the general formula () is usually 1:1.5 to 3, preferably 1:2 to 2.5.
Although this reaction proceeds without the use of a catalyst, it is preferable to use an inert organic solvent such as toluene or xylene. Further, a deoxidizing agent such as triethylamine, pyridine, etc. can also be used. The reaction temperature is 10-150℃, more preferably 10-150℃
It is 100℃. Here, the halogenated carboxylic acids used as raw materials include monochloroacetic acid, monobromoacetic acid, 3-chloropropionic acid, 3-bromopropionic acid, 4-chlorobutyric acid, 4-bromobutyric acid, 5-chlorovaleric acid,
Examples include -bromovaleric acid and lower alkyl (eg, methyl, ethyl, propyl, butyl) esters thereof, and it is particularly preferable to use lower alkyl esters of halogenated carboxylic acids. In the second stage reaction, the reaction product in the first stage and 4-hydroxy-
This reaction is carried out by reacting 2,2,6,6-tetramethylpiperidine compound with a basic catalyst in the presence of a basic catalyst, and after the completion of the reaction in the first step, the reaction product is taken out from the reaction solution. Alternatively, the reaction solution may be used as it is without being taken out. In this reaction, 4-hydroxy-2,2,
The amount of 6,6-tetramethylpiperidine compound used is usually the starting material 4-amino-2,2,6,
1.5 for 6-tetramethylpiperidine compound
-4 times, preferably 2-2.5 times by mole. Although the reaction proceeds without using a solvent, it is preferable to use an inert organic solvent such as methanol, toluene, or xylene. Basic catalysts include potassium hydroxide, sodium hydroxide, lithium hydroxide,
Lithium aluminum hydride, sodium boron hydride, sodium hydride, lithium hydride, sodium amide, sodium t-butoxide, potassium t-butoxide, sodium methoxide, potassium methoxide, sodium phenoxide, potassium phenoxide, sodium metal ,
Examples include metallic potassium, among others, potassium t-butoxide, sodium methoxide,
Preference is given to using sodium phenoxide and sodium hydroxide. The amount of the catalyst to be used is 0.01 to 1 mole, preferably 0.1 to 0.5 mole, relative to the starting material 4-amino-2,2,6,6 tetramethylpiperidine compound. The reaction temperature is 0-150°C, preferably 10-50°C. Typical 2,2,6,6- thus produced
Tetramethylpiperidine derivatives are shown in Table 1, but when using the method of the present invention, depending on the reaction conditions, a monoester-exchanged product may be simultaneously produced, and it can be obtained as a mixture with a diester-exchanged product, which is the compound of the present invention. However, when used as a stabilizer or the like, there is no particular problem in using such a mixture as it is.

【table】

[Table] The present invention will be explained below with reference to Examples. Example 1 Production of compound (-1) 10.0 g (0.064 mol) of 4-amino-2,2,6,6-tetramethylpiperidine was dissolved in 60 ml of toluene and kept at 60°C. To this was added 16.1 g (0.13 mol) of monochloroethyl acetate over 10 minutes, and then the mixture was kept at 80°C for 1 hour. After the reaction was completed, the reaction solution was washed with saturated sodium bicarbonate solution and then with water, and the toluene layer was concentrated to obtain 19.7 g of a transparent oily liquid. 4.6 g (0.014 mol) of this oil and 5.1 g (0.032 mol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine were dissolved in 50 ml of methanol, and 1.2 g of 28% sodium methylate was dissolved therein.
(0.0064 mol) and refluxed for 2 hours. After the reaction is complete, the solvent is distilled off and the residue is diluted with 30 ml of toluene. This was poured into 30 ml of ice water, separated and washed with water, and then the solvent was distilled off to obtain pale brown crude crystals. The crude crystals were recrystallized from a mixed solvent of ethyl acetate and hexane to obtain 6.9 g of white crystals (purity: 80%), which was the desired product. Yield 84%, m, p80~83℃ Molecular ion peak of mass spectrum 550 H'-NMR spectrum δ = 5,2 (t, 2H), 3,6 (s, 4H), 3,2 (t, 1H) ), 1,9 (d, 4H), 1,8 (d, 2H), 1,2 (m, 45H) Elemental analysis value (as C ₃₁ H ₅₈ N ₄ O ₄ ) C H N Experimental value (%) 68.01 10.80 9.98 Calculated value (%) 67.58 10.63 10.17 By repeating this recrystallization three times from n-hexane solvent, purity 97.5%, mp.108~
Obtained white crystals at 109℃. Molecular ion peak of mass spectrum Same as above'H-NMR spectrum Same as above Elemental analysis value (as C31H58N404) C H N Experimental value (%) 67.70 10.70 10.05 Calculated value (%) 67.58 10.63 10.17 Example 2 Production of compound (-3) 1 -Methyl-4-amino-2,2,6,6-tetramethylpiperidine 10.0g (0.059 mol) in 60
ml of toluene and reacted with 16.1 g (0.13 mol) of ethyl monochloroacetate in the same manner as in Example 1 and worked up in the same manner to obtain 17.7 g of a clear oily liquid. 4.8 g (0.014 mol) of this oil and 1-methyl-
5.5 g (0.032 mol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine was reacted in the same manner as in Example 1 and purified in the same manner to obtain 7.8 g of white crystals, which was the desired product. Yield 82%, m.p85-88℃ Molecular ion peak in mass spectrum 592 Elemental analysis value (as C ₃₄ H ₆₄ N ₄ O ₄ ) C H N Experimental value (%) 62.56 9.80 9.61 Calculated value (%) 62.78 9.88 9.45 Example 3 Production of compound (-5) 10.0 g (0.064 mol) of 4-amino-2,2,6,6-tetramethylpiperidine was dissolved in 60 ml of toluene, and 19.6 g (0.13 mol) of 4-amino-2,2,6,6-tetramethylpiperidine was dissolved in 60 ml of toluene. -Ethyl chlorobutyrate was reacted in the same manner as in Example 1 to obtain 21.6 g of a clear oily liquid as a post-treatment. 5.0 g (0.014 mol) of this oil and 5.1 g (0.032 mol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine were reacted in the same manner as in Example 1, and purified in the same manner to obtain the desired product. A white crystal that is
7.0g was obtained. Yield 80%, m.p90~93℃ Molecular ion peak in mass spectrum 592 Elemental analysis value (as C ₃₄ H ₆₄ N ₄ O ₄ ) C H N Experimental value (%) 62.89 9.70 9.40 Calculated value (%) 62.78 9.88 9.45

Claims (1)

[Claims] 1. General formula (In the formula, R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group, and R ₃ represents an alkylene group having 1 to 4 carbon atoms.) 2,2,6,6-tetramethylpiperidine represented by Derivative 2 General formula (In the formula, R ₁ represents a hydrogen atom or a methyl group.) 4-Amino-2,2,6,6-tetramethylpiperidine compound represented by the general formula (In the formula, X is a halogen atom, R ₃ is a carbon number 1
~4 alkylene group, R ₄ represents a hydrogen atom or a lower alkyl group. ) by reacting the halogenated carboxylic acids shown in
Then the general formula (In the formula, R ₂ represents a hydrogen atom or a methyl group.) It is characterized by reacting a 4-hydroxy-2,2,6,6-tetramethylpiperidine compound represented by the following in the presence of a basic catalyst. general formula (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above.) A method for producing a 2,2,6,6-tetramethylpiperidine derivative represented by the following formula.